Apparatus for initiating and drilling deviating curved bores from existing vertical wll bores



June 16, 1953 J. A. ZUBLIN APPARATUS FOR INITIATING AND DRILLINGDEVIATING CURVED BORES FROM EXISTING VERTICAL WELL BORES 5 Sheets-Shet 1Filed Jan. 17, 1951 JhAZMha a W ATTORNEYS June 16, 1953 J ZUBLIN2,642,267

APPARATUS FOR INITIATING AND DRILLING DEVIATING CURVED BORES FROMEXISTING VERTICAL WELL BORES Filed Jan 17, 1951 5 Sheets-Sheet 2 v rlllfflllllllllllllpl!Ill!!!lllIlllfllIllll/ll/IfllIll/f!llIll/IIIIIIll/IIIIIfl/lfllll/f'lIllll/fIl/I/IAIll 8 VII II! as VII/IY \QHW IIIIIIIIIII IIII i:

III III! I i lllllll'lii ATTORNEYS J1me 1953 J. A. ZUBLIN 2,642,267

I APPARATUS FOR INITIATING AND DRILLING DEVIATING CURVED BORES FROMEXISTING VERTICAL WELL BORES Filed Jan. 17, 1951 B SheetS-Sheet 5 JMIMWATTORNEYS Patented June 16, 1953 UNITED STATES PATENT OFFl-(ZE.

. 254L267 1 APPARATUS FOR- INITIATING AND DRILL- ING DEVIATING CURVEDBORES FROM EXISTING VERTICAL WELL BLORES John. A. Zublin, Los; Angeles,I Calif;

Application January 17, 19'51, Serial No; 2063364 The present inventionrelates toz-an. apparatus forinitiating and' drilling lateralcurvedzbores: detrvi'ating from an existing: vertical wellibore;

More particularly; it is an o.bject: and. purpose ofthe presentinventionto provide an apparatus whichis particularly efficacious inothedrillingof lateral bores deviating; from: existing .wellib'ores in hardformations such as. limestone and like hard formations. p

More: specifically, it1is; an: obj ect; and. purpose. of the. presentinvention to provide an apparatus which: constitutes amimprovementt-on:an appara tus hereriofore developed. Icy-me; such, for: exam;- ple; asdisclosed; and. claimed in. my Unitedi States Batenti2;382,9.&3z Theprior: apparatus developed by; mehas. great; value. and. is.particularly: well suited for useirr drilling, inrelatively. softform'aetions. Hwever; limestone; formations? which are formed: in nature: asgasolid block are: difficult to penetrate and; the improvements:presented-by the present: invention renderthe drilling of; deviatingbores, in such formations economical and: practicali.

' In its more specific: aspects; the-presentinven- .tion contemplatespressing a drilling, bit' sidewardlyinto the? walk of. an existingwell.- bore with energy furnished by reaction ofa-nelongated normallycurved. resilient? flexible drill guide. forcibly flexed to: a. lessercurvature: within the: existing well boreand inaugmenting the:forcewit-hwhich the bit-is pressed sidewardlyintothe-wall of. the existngwell: 'borerby the; deflecting forces" imposed; on the bit as. theresilient drill. guideis lowered; over. the inclined: surfaceoi, avwhipstock insertedin thewell borein; advance ofthe normally curved.flexible resilient. drill guide;

Further and: more. detailed; objects and; advantages of the. invention;will become apparent, as the; description) proceeds,- V which will be.given by reference to -the accompanying drawings, wherein Figure 1.is.aside. elevation. of one formofi an paratus showingparts, broken. awaytor, clarity.

Figure.- 2 is. a. front. elevationiof. theilower. portionoii the,embodiment. of'Figure 1.v

Figure 3 is, a planview taken on line 3-3 of Fi ure 2'.

Figured isa crossesectional view albngtheline 4j-4 of. Figure 2; V

Figure 5 is a side" elevation with parts shown in section at a secondembodiment ofan apparatus oonfcccming tothe present invention.

Figure Gisa fronirelevational view-of the-lower portion of theembodiment shown in Figure 5:

Figure 7 is: atransverse sectional view on the 1ine T-'l orF-igure fitaken imtlie direction of the arrows;

' 2=Glaims. (Cl..255.--1'.6)

Figure 8 is: aside elevation. with-parts; shown in section of a thirdembodiment of. apparatus; cor:- responding to the present. invention.

Figure 9' is atransverse sectional; view: on the line 99 of'Figurei8ktaken imthe direction of the arrows.

Figurel'O is a sideelevationaliview With parts shown in sectionof afourth embodiment of; an. paratus conforming. toe the invention:

I Figure. 1'11 is a d'etailedicrosseseotional view of the apparatus ofFigure I05 showingz'the: position a-ssumed bythe-Vfi-fiOlJSielEIIIBDItSTQf? the apparatus during initiating of. the:drilling. of: a. deviating bore. 1

Figure 121 is; a. transverse sectional. viewon. the line l 2-42 ofFigure 10 taken inithe directionof the arrows;

Figure: 13': is a: transverse sectional. view. onthe line l3l3 of Figure10 takeninlthed'irection of the. arrows;

Referring" to the embodiment; oh the invention illustrated inFigures .1to 4.; thezcombinationapparatus shownin Figure 1 is-adaptedzto: becarried in its entirety at the lower endloffasubstantially rigid drillstring such as indicated at I 0 in Figure 8, which substantially rigid:drill. string: extend'seto the surface -of the-well and is adapt'ed tobe. driven Figurelembraces the flexible n0n-resilientidrillstring-section- I l", the-upper end ofwhich isoroken 'figurationoi'thedrill guide; [:2 is; such as to'canse away in Figurel but which it:will be understood is; connected to the rigid drill string in. the samemanner that the flexible non-resilient drill string section bearing thesame reference numeral H in Figure 8-- isillustrated in that figure ascon nected to the normally rigid drill string Hit The flexible'nonresilient drill string section ll may" preferablytake the form of thenon-resilient flexible drill pipe more par ticularly disclosed in mypriorUnited States Patent 2515366 issued on July= 18, 19501 It will-beappreciated thati depending upon the length of the deviating boredesired to be drilled; one or more non-resilient flexible?drillpipesections l=lmay be employed in the apparatus. g Below=thefi'exiblenon resili'ent drill string section l 'l thereis positioned thenormally curved flexible resilient" drill guide I92 It. will be understiood that: the. normal: unstressed: curved: com

the: same; to? be; flexed to a. substantially lesser curvahira aninsertion: into, an. existing; well; bore to thereby storezenergn insaididrill guide: effective tosf'orce the; bit, is; carried: at t-he:lower end: of the drill guide I2 sidewardly against the wall of anexisting vertical well bore.

The flexible non-resilient drill string section I I in reduced form asindicated at Ila in Figure extends downwardly through the interior ofthe hollow normally curved flexible resilient drill guide I2 and thereduced portion I Ia of the flexible non-resilient drill string sectionI I constitutes the rotating means for driving the drill bit I3 to whichit is connected at its lower end. Both the flexible non-resilient drillstring section I i and the reduced extension. I Ia thereof are made upof small independent units interconnected by dovetailed slots in themanner more specifically described in my United States Patent 2,515,356hereinabove referred to. The normally curved flexible resilient drillguide I2 is preferably of the type disclosed in my United States Patent2,515,365 issued July 18, 1950. This normally curved flexible resilientdrill guide is formed of tubular metal pipe having a slot through thewall thereof extending in a generally helical path along and around thepipe. The sides of the slot are provided with intermeshing andinterlocking dovetailed teeth. By way of illustration it is advantageousto employ a normally curved flexible resilient drill guide I2 which hasan over-all length of about It feet and a curvature in its unstressedcondition that lies on a radius of about 16 feet. Under such conditionsthe height of the are formed by the guide when in unstressed conditionwill .be found to be about 30 inches. When such a drill guide isinserted into a well bore, depending somewhat on the diameter of thewell bore, the lower end of the drill guide will be forced against theside wall of the vertical bore in the absence of the augmenting forceprovided by the whipstock under a pressure of the order of from 100 to700 pounds.

The specific manner in which the reduced portion Ha of the flexiblenon-resilient rotating drill string section II is mounted for rotationwithin the outer normally curved flexible resilient drill guide I2 isillustrated in greater detail in my copending application Serial No.189,591 filed October 11, 1950, now Patent 2,585,207.

In the embodiment of the invention shown in Figures l-4, the lower endof the normally curved flexible resilient drill guide I2 extends throughthe casing-like collar I I at the upper end of the whipstock memberindicated generally at I5. The opening I6 through the casing-like collarI4 is preferably in this embodiment slightly inclined from the verticalaxis extending through the whipstock member I5 and the opening I6 is ofa b diameter only slightly greater than the diameter of the normallycurved flexible resilient drill guide I2. The arrangement is such thatthe bit l3 positioned below the casing-like collar I4 will not passthrough the opening I6. Thus the entire whipstock member I5 issuspendedfrom the drill string and may be lowered into and withdrawn from thewell with the drill string. The lower end of the whipstock member I5carries the fishtail bit-like member l1 and the length of theintermediate coupling I8 will determine the elevation from the bottom ofthe well at which the inclined face I9 of the whipstock member I5 willbe positioned. It will be appreciated that when the drill string islowered into the well it can be oriented to insure the drilling of adeviating bore such as indicated at 20 in Figure 1 in any desiredazimuth and the fishtail bit-like member I I when it strikes the bottomof the Vertical bore will act to hold the Whipstock 4 member I5 in suchdesired oriented position. The screw 2i is employed to interlock thelower end of a normally curved flexible resilient drill guide I2 and thecasing-like collar I4 so as to hold the bit I3v substantially whollywithin the the teeth of the cones 22 of the bit I3 are held out ofcontact with the walls of the well bore 23 as the apparatus is insertedinto an existing well bore thereby avoiding wear on the teeth andunwanted gouging against the side wall of the existing vertical wellbore. When the fishtaillike bit member i1 carried at the lower end ofthe whipstock member I5 strikes the bottom of the existing vertical Wellbore, the release at the surface of the well of the weight of the drillstring shears the pin 2| which allows the normally curved flexibleresilient drill guide I2 to be lowered through the opening I6 in theeasing-like collar Id and to advance over the inclined surface I9 of thewhipstock member"). It will be observed that the bit I3 carrying thecones 22 is thus forced against the side wall of the well bore I3 by theenergy stored in the nor= mally curved flexible resilient drill guide I2which has been forcibly flexed to a lesser curvature by insertion intothe well bore which is augmented by the wedging forces created throughthe advancement of the drill guide I2 over the inclined face I9 of thewhipstock member I5. It will be appreciated that the release of weightof the drill string at the surface of the well will insure the creationof very substantial augmenting forces as the drill guide l2 moves overthe inclined surface I9 tending to force penetration of the formation bythe driven bit I3.

The several embodiments of the invention have in common the feature ofaugmenting the lateral directing force imparted to the bit by the energystored in the normally curved flexible resilient drill guide I2 throughpassage of the latter under controlled pressure over the inclinedsurface of an associated whipstock.

Referring to the embodiment of Figure 5, it will be observed that theflexible non-resilient drill string section II'a is of substantiallylesser diameter than the normally curved flexible resilient drill guideI2 so that the flexible nonresilient drill string section I Ia canextend downwardly completely through drill guide I2 as indicated indotted lines and be connected at its lower end to the drill bit I3a. Inthis embodiment there is provided an elongated casing or sleeve 24carrying a collar 25 at its upper end. The opening 25 in the collar 25has a diameter only slightly greater than the diameter of the flexiblenon-resilient drill string section Na and thus considerably less thanthe outside diameter of the drill guide I2. The arrangement is such thatthe upper end of the drill guide I 2 abuts the shoulder 21 of the collar25 and prevents upward withdrawal of the drill guide I2 through thecollar 25. The sleeve 24 is substantially longer than the over-alllength of the drill guide I2 and the bit I30. so that the sleeve 24completely encases the guide I2 and bit I30; during insertion of theapparatus into an existing vertical well bore. It will be appreciatedthat the friction developed between the casin 24 and the normally curvedflexible resilient drill guide l2 created by forcibly flexing the drillguide I2 from its normally curved configuration to the straightconfiguration occupied thereby in the position shown in Figure 5 will bewholly adequate to ti'onshipshown in Fig-ure 5' during theinsertion of"the apparatus intoan existing well borer It Will'be'further observedthat thebit l3a= carrying cones 22a is house'd within the hollowcasing:24 during insertion of the apparatus in the verti car well boresothat-contact of'the teeth of the cones with the wall of the verticalwell bore is completely'avoided. I

A portion of the wall of the casing 24: near the bottom thereof is cutaway as-indi'cated: at 2'8 to provide a-- window through whichfthe bitl3a, the drill guide 1-2 and the flexible noneresilient drill stringsection Ha may be; projected. Opposite the window: providedv by thecut-out portion; 28- isdisposed the inclined surface 28 of theywhipstock' member 30 welded: as indicated at 3] to the casing 24; Thewhipstockg member 3-0 is connected through coupling 32'. with thefishtail-like bit member 33: which functions in altogether a similarmanner to: the functioning of the fishtail-like bit member H of" theembodiment: of Figure l. Rib-like members 34,35 and 36 are welded to theouter wall= of the casing; 24 ("see Figure 7:) and serve the two-foldpurposeaof acting as sled runner-like members during the insertion ofthe apparatus intoan existing well boreand-iurther actin conjunction:with the fish:-

tail-like bit member 33-" inholding: the apparatus in at desiredposition of orientation during; the drilling of a deviating bore.

In the embodiment exemplified: by Figures: 54 no shear'pin: is requircd;The entire combination is insertableinto and Withdrawable: front a wellhere as a unit; In this embodiment when the fishtailelike bit member"33- strikes the: bottom of the existing well bore, the release of weighton: the drill string at the surface of the well will be suihoient toforce the normally curved flexibleresilient drill guide l-2 carrying thebit 13 down through the upper closedi portion of the casing 24 and overthe inclined surface as oflthewhipstock member. 353., As soon as thenormally, curved flexible resilient drill guide. I12: begins to emergethrough the window provided; by theJcut-outportion 28', the energystoredlthe'reindue to. itsl-havi'ng been flexed 't'o a lesser curvatureisreleased and" effected'to force the bit [3a against. the. side Wall ofthe existing we'll; bore and the force thus applied; to. the bit is.augl ment'edlby the wedging actionoccasionedlthrough passage of thedrill" guide f2 downwardly :over the inclined surface 29 of thewhipstock; The embodiments of Figures 5-7 have some advantages overcertain other embodiments herein disclosed in that no elongating strainis placed on the normally curved flexible resilient drill guide 12 inwithdrawing the apparatus from the well bore which of course is not thecase with the more simplified embodiment of Figure 1 which has, howeverthe advantage of being more economically produced.

The embodiment of Figure 8 presents a variant of the embodiment ofFigure 5 in that in Figure 8 the casing 24a is provided with a muchlarger cut-out portion 28a than is the case in 24 of Figure 5. Thus inthe embodiment of Figure 8" the normally curved flexible resilient drillguide [2 is held in interlocked relationship with the casing 24a by theshear pin 3'1, the arrangement being such that the drill bit I3b is heldwholly within the confines of the circumference of the casing 24a whenthe apparatus is inserted into an existing vertical well bore. When the'fishtail-like bit member 38 strikes the bottom a oii'the existlngvertlcal bor the pin 31 is sheared ofij the weight of the drill stringand the bit I 3 together with the drill guide l2 then pass downwardlyover the inclined face 39 of the whipstoch member 40 with the resultthat the laterals force upon the-bit l3b represents the energy stored"in the drill" guide I 2 as; augmented bythe wedging force incidenttopassing the same over the inclined surface 39 of the whipsto'c'li- E0When the apparatus of the embodiment of Figure 8 withdrawn from thewell, the coupling member 4* l carries laterally extending ribs 42 whichengage the shoulder 43"0f the collar 25w at the upper end of the casing24a.

Thus; inthis embodimentno longitudinal strain is imposed oneithertheflexible nonre'silient drill string sect-ion l il or'the' drillguide l2 during' withdrawal of the apparatus' from the well since" thecoupling 4 lis directly connected to the lower end of,-the substantiallyrigid drill Referring to theembodiment illustrated in Figures/ 110-13inclusive, it will be; observed that this: embodiment is primarilyintended for the drillingof relatively 'sharp deviating bores from avertical well" bore; that is, deviating bores of no greater length thanthe length" of the normallycurved flexible resilient drill guide l2. Itwill be understood that in this embodiment an inner:flexible-non-resilient-drill string section of smaller diameter than thedrill guide l2- extends down througntne drillguide l2 for driving thedrill bit l3c. The upper end of the inner flexible norr-resilienti drillstring member is connected through the; tubular" rigid coupling 44 tothe lower end of the substantially rigid drill string H! The rigid:tubular coupling 44 isprovided Wlththe annulanshoulde'r'45' fora-purpose which will be. presently: described. The casing 24bin thisembodiment ispro'vid'e'cl with an extended cut-out portion; 28b and with a collar 255 at the movement with respectto the casing 24b. 'Thelowen end of the casing 24b is provided with a tubular" collar 4 8*having a-key-way 49 extending along one side: of the tubularopening 5t.-An

elongated coupling member 51 interconnects the 'wl' lipstock member 4i.and the fishtail-like bit member 52. The elongated member 5| is providedwith a key 53 which moves through the keyway 49 in the collar 48 andprevents relative rotation of the whipstock member 4! with respect tothe casing 44b. The member 5| is of a length substantially equal to theover-all length of the casing 241). When the fishtail-like bit member 52strikes the bottom of the vertical well bore due to the fact thatcoupling 44 can move down through the tubular collar 25b for a distanceequal to the space between the top of the collar 25b and the shoulder45, the shear pin 46 will be sheared off by the limited down- I wardmovement of the drill guide l2 with respect to the casing 241). When theshoulder or tubular coupling 44 strikes the top of the collar 25b nofurther relative longitudinal movement between the drill guide l2 andthe casing 24b will occur. move downwardly around the whipstock member41 and downward pressure by weight of the drill string through shoulder45 on the top of the However, the casingl24b is free toshown in Figure11.

collar 251) will force the casing 24b downwardly over the whipstock 4!and cause the latter to move into a position between the flexible drillguide 12 and the casing 24 as more particularly As the casing 241) andthe dl lll guide 12 move downwardly with respect to lth'e whipstock 41,the bit l3c is forced laterally linto the formation by the energy storedin the (drill guide 12 as augmented by the passing "thereof over theinclined surface 54 of the whipstock 41. In this embodiment when theapparatus is withdrawn from the well, the upper end of the drill guide12 strikes the lower face of the -collar 25b and thus there is nolongitudinal strain on the drill guide 12 during withdrawal of theapparatus fromthe well- From the foregoing it will be appreciated thatthe basic method of the present invention is susceptible of beingpracticed by any one of numerous apparatus embodiments. In all instancesthe laterally directing force applied to the bit represents the energystored in a normally curved flexible resilient drill guide which hasbeen forcibly flexed to a lesser curvature as augmented by theadditional forces developed through passage of the drill guide underpressure downwardly over an inclined surface of a whipstock, throughwhich medium lateral deviating bores may be effectively drilled in hardformations of the character of limestone and the like.

Having-thus described claim is:

1. An apparatus adapted to be carried in its entirety at the lower endof a rotary drill string for drilling curved bores deviating from anexisting well bore, comprising in combination a 1'0- tatable flexibledrii'i string section made up of a plurality of units so interconnectedas to per mit of limited relative angular movement of adjacent units inall directions, a normally curved metallic flexible resilient drillguide surrounding at least a portion of said flexible drill stringsection said guide having a slot in the wall thereof extending in agenerally helical path around and along said guide, the upper end or"said flexible drill string section being connectable to the lower end ofthe rotary drill string, a drill bit carried at the lower end of saidflexible drill string section for rotation therewith, an elongatedsleeve surrounding at least a portion of said rotatable flexible drillstring section and said flexible resilient drill guide and insertable myinvention, what I therewith into an existing well bore, a whipstockhaving an exposed camming face secured at the lower end of said sleevesaid normally curved flexible resilient drill guide being effective toexert pressure on the bit in the same direction as that of the wedgingaction of said whipstock whereby upon relative vertical movement of saidbit and said whipstock the bit is forced sidewardly, by the wedgingaction of said whipstock, and the action of said normally curvedflexible resilient drill guide against the wall of the existing bore toinitiate and thereafter drill a deviating bore.

2. An apparatus adapted to be carried in its entirety at the lower endof a rotary drill string for drilling curved bores deviating from anexisting well bore comprising, in combination, a rotatable flexibledrill string section made up of a plurality of units capable of limitedrelative angular movement in all directions; a sub having a laterallyextending shoulder carried at the upper end of said flexible drillstring section, the upper end of said sub being connectable to the lowerend of a rotary drill string; a drill bit carried at the lower end ofsaid flexible drill section; an elongated rigid sleeve substantiallyentirely surrounding, within the confines of its circumference, saidflexible drill section, sub and bit during insertion of said apparatusinto an existingwell bore; a collar carried at the upper end of saidsleeve for engagement with said shoulder of said sub when said flexibledrill string section is raised to permit withdrawalof said apparatus asa unit from a well bore; and a whipstock having an exposed camming facecarried at the lower end of said sleeve.

JOHN A. ZUBLIN.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,814,601 McCaskey Sept. 2, 1919 1,886,820 Lee Nov. 8, 19322,170,284 Eastman Aug. 22, 1939 2,207,920 Hughes July 16, 1940 2,296,161Hall, Jr Sept. 15, 1942 2,336,338 Zublin Dec. 7, 1943 2,338,788 WalkerJan. 11, 1944 2,498,159 Gammill Feb. 21, 1950 2,506,799 Livingston May9, 1950 2,571,644 Zublin Oct. 16, 1951

